Cutaneous leiomyosarcoma: a retrospective review of 45 cases.

Primary cutaneous leiomyosarcoma (LMS) is a rare soft tissue tumour type with two subtypes, dermal and subcutaneous. As deeper tumours confer a worse prognosis, they require a more aggressive approach. Conversely, a more conservative surgical approach for dermal LMS has been suggested. Few studies have comprehensively reported both clinical surgical and histological excision margins. Therefore, we sought to provide margin recommendations based on our experience and review of the existing literature. We undertook a retrospective case-note review (1998-2019) of cutaneous LMS management to establish histological/surgical margins using pathology/electronic patient records. The diagnosis was made and classified by an experienced dermatopathologist according to the World Health Organization classification. In the dermal LMS cohort (n = 35), mean peripheral and deep histological margins were 5.4 mm (range 0.5-20) and 5.6 mm (range 0.1-14.5), respectively. The incomplete excision rate was 31% (11 of 35). There were no recurrences. In the subcutaneous LMS cohort (n = 10), mean peripheral and deep histological margins were 5.7 mm (range 0.2-14) and 1.1 mm (range 0.2-1.7), respectively. The incomplete excision rate was 40% (4 of 10). The recurrence rate was 20% (2 of 10) despite achieving histological clearance after 1 year. One lung metastasis occurred 1 year following an adequately excised primary scalp LMS. Thus, for dermal LMS we propose a clinical margin of 5-10 mm (depending on lesion size) at the initial excision or at scar re-excision following involved/close histological peripheral and/or deep margins (i.e. < 1 mm). For subcutaneous LMS, we suggest a clinical margin of 15-20 mm (depending on lesion size) to achieve a peripheral histological clearance of 10 mm and negative deep margin (i.e. > 1 mm), down to the periosteum/fascia/muscle according to anatomical site. If this is not achieved, a re-excision would be recommended. However, prospective studies are needed for optimal guidance.

Mutant Ras and inflammation-driven skin tumorigenesis is suppressed via a JNK-iASPP-AP1 axis.

Concurrent mutation of a RAS oncogene and the tumor suppressor p53 is common in tumorigenesis, and inflammation can promote RAS-driven tumorigenesis without the need to mutate p53. Here, we show, using a well-established mutant RAS and an inflammation-driven mouse skin tumor model, that loss of the p53 inhibitor iASPP facilitates tumorigenesis. Specifically, iASPP regulates expression of a subset of p63 and AP1 targets, including genes involved in skin differentiation and inflammation, suggesting that loss of iASPP in keratinocytes supports a tumor-promoting inflammatory microenvironment. Mechanistically, JNK-mediated phosphorylation regulates iASPP function and inhibits iASPP binding with AP1 components, such as JUND, via PXXP/SH3 domain-mediated interaction. Our results uncover a JNK-iASPP-AP1 regulatory axis that is crucial for tissue homeostasis. We show that iASPP is a tumor suppressor and an AP1 coregulator.

Dual-specificity protein phosphatase DUSP4 regulates response to MEK inhibition in BRAF wild-type melanoma.

BACKGROUND: Aiming to improve treatment options for BRAF wild-type melanoma, we previously conducted the DOC-MEK study of docetaxel with MEK inhibitor (MEKi) selumetinib or placebo, revealing trends to prolongation of progression-free survival (hazard ratio 0.75, P = 0.130), and improved response rates (32% vs 14%, P = 0.059) with docetaxel plus selumetinib. NRAS status did not associate with outcome. Here, the aim was to identify novel biomarkers of response to MEKi. METHODS: A MEK 6 gene signature was quantified using NanoString and correlated with clinical outcomes. Two components of the gene signature were investigated by gene silencing in BRAF/NRAS wild-type melanoma cells. RESULTS: In melanomas of patients on the selumetinib but not the placebo arm, two gene signature components, dual-specificity protein phosphatase 4 (DUSP4) and ETS translocation variant 4 (ETV4), were expressed more highly in responders than non-responders. In vitro, ETV4 depletion inhibited cell survival but did not influence sensitivity to MEKi selumetinib or trametinib. In contrast, DUSP4-depleted cells showed enhanced cell survival and increased resistance to both selumetinib and trametinib. CONCLUSIONS: ETV4 and DUSP4 associated with clinical response to docetaxel plus selumetinib. DUSP4 depletion induced MEKi resistance, suggesting that DUSP4 is not only a biomarker but also a mediator of MEKi sensitivity. CLINICAL TRIAL REGISTRATION: DOC-MEK (EudraCT no: 2009-018153-23).

IGF-1R inhibition induces schedule-dependent sensitization of human melanoma to temozolomide.

Prior studies implicate type 1 IGF receptor (IGF-1R) in mediating chemo-resistance. Here, we investigated whether IGF-1R influences response to temozolomide (TMZ), which generates DNA adducts that are removed by O6-methylguanine-DNA methyltransferase (MGMT), or persist causing replication-associated double-strand breaks (DSBs). Initial assessment in 10 melanoma cell lines revealed that TMZ resistance correlated with MGMT expression (r = 0.79, p = 0.009), and in MGMT-proficient cell lines, with phospho-IGF-1R (r = 0.81, p = 0.038), suggesting that TMZ resistance associates with IGF-1R activation. Next, effects of IGF-1R inhibitors (IGF-1Ri) AZ3801 and linsitinib (OSI-906) were tested on TMZ-sensitivity, cell cycle progression and DSB induction. IGF-1Ri sensitized BRAF wild-type and mutant melanoma cells to TMZ in vitro, an effect that was independent of MGMT. Cells harboring wild-type p53 were more sensitive to IGF-1Ri, and showed schedule-dependent chemo-sensitization that was most effective when IGF-1Ri followed TMZ. This sequence sensitized to clinically-achievable TMZ concentrations and enhanced TMZ-induced apoptosis. Simultaneous or prior IGF-1Ri caused less effective chemo-sensitization, associated with increased G1 population and reduced accumulation of TMZ-induced DSBs. Clinically relevant sequential (TMZ → IGF-1Ri) treatment was tested in mice bearing A375M (V600E BRAF, wild-type p53) melanoma xenografts, achieving peak plasma/tumor IGF-1Ri levels comparable to clinical Cmax, and inducing extensive intratumoral apoptosis. TMZ or IGF-1Ri caused minor inhibition of tumor growth (gradient reduction 13%, 25% respectively), while combination treatment caused supra-additive growth delay (72%) that was significantly different from control (p < 0.01), TMZ (p < 0.01) and IGF-1Ri (p < 0.05) groups. These data highlight the importance of scheduling when combining IGF-1Ri and other targeted agents with drugs that induce replication-associated DNA damage.

Dsh homolog DVL3 mediates resistance to IGFIR inhibition by regulating IGF-RAS signaling.

Drugs that inhibit insulin-like growth factor 1 (IGFI) receptor IGFIR were encouraging in early trials, but predictive biomarkers were lacking and the drugs provided insufficient benefit in unselected patients. In this study, we used genetic screening and downstream validation to identify the WNT pathway element DVL3 as a mediator of resistance to IGFIR inhibition. Sensitivity to IGFIR inhibition was enhanced specifically in vitro and in vivo by genetic or pharmacologic blockade of DVL3. In breast and prostate cancer cells, sensitization tracked with enhanced MEK-ERK activation and relied upon MEK activity and DVL3 expression. Mechanistic investigations showed that DVL3 is present in an adaptor complex that links IGFIR to RAS, which includes Shc, growth factor receptor-bound-2 (Grb2), son-of-sevenless (SOS), and the tumor suppressor DAB2. Dual DVL and DAB2 blockade synergized in activating ERKs and sensitizing cells to IGFIR inhibition, suggesting a nonredundant role for DVL3 in the Shc-Grb2-SOS complex. Clinically, tumors that responded to IGFIR inhibition contained relatively lower levels of DVL3 protein than resistant tumors, and DVL3 levels in tumors correlated inversely with progression-free survival in patients treated with IGFIR antibodies. Because IGFIR does not contain activating mutations analogous to EGFR variants associated with response to EGFR inhibitors, we suggest that IGF signaling achieves an equivalent integration at the postreceptor level through adaptor protein complexes, influencing cellular dependence on the IGF axis and identifying a patient population with potential to benefit from IGFIR inhibition.

The current state of play in the histopathologic assessment of alopecia: two for one or one for two?

The histopathologic assessment of a scalp biopsy for alopecia relies largely on the quality of the specimen provided for evaluation. There are a number of different protocols in the literature which have been proposed over the years, but no consensus has yet been reached as to the appropriate number of biopsies to be taken, or to which sectioning technique is the gold standard for achieving the best diagnostic yield. We herein review the pros and cons of the various protocols and share the experience with our St John's protocol.

Dermoscopy: Ex vivo visualization of fleas head and bag of eggs confirms the diagnosis of Tungiasis.

Tungiasis, caused by the impregnated female sand flea Tunga penetrans, is increasingly common in returned travellers from endemic areas. Clinical suspicion is raised by the clinicodermoscopic correlation, leading to rapid treatment which involves extraction of the intact flea. Ex vivo dermoscopy demonstrates the parasite's head and distended abdomen full of eggs, confirming the diagnosis.

Thyrotoxicosis with pegylated interferon alfa-2b.

BACKGROUND: Despite adequate surgery, a diagnosis of stage III melanoma carries a high risk of relapse, and hence mortality. Interferon alfa is the only treatment that has currently been shown to alter the natural history of the disease, delaying relapse-free survival, particularly in patients with micrometastatic disease. There is also recent evidence of a prognostic advantage conferred by the development of autoimmune conditions in patients receiving adjuvant interferon therapy. OBSERVATIONS: We present the case of a 27-year-old woman with stage IIIa melanoma who was entered into the European Organisation for the Research and Treatment of Cancer 18991 trial of 5-year adjuvant treatment with pegylated interferon (peginterferon) alfa-2b. The patient developed thyrotoxicosis 3 months after commencing treatment, which required treatment with propylthiouracil. The degree of thyrotoxicosis corresponded closely to the dose of peginterferon alfa-2b given. However, in this patient, the hyperthyroidism resolved spontaneously after 4 years when peginterferon treatment was still ongoing. Seven years following the initial diagnosis, the patient has not had disease relapse. CONCLUSION: Hyperthyroidism is less common than hypothyroidism as a consequence of interferon therapy, and this case is atypical in that it resolved spontaneously during interferon therapy but is in accordance with the recent evidence of a positive association between interferon-associated autoimmunity and prognosis.

Invariant NKT cells modulate the suppressive activity of IL-10-secreting neutrophils differentiated with serum amyloid A.

Neutrophils are the main effector cells during inflammation, but they can also control excessive inflammatory responses by secreting anti-inflammatory cytokines. However, the mechanisms that modulate their plasticity remain unclear. We now show that systemic serum amyloid A 1 (SAA-1) controls the plasticity of neutrophil differentiation. SAA-1 not only induced anti-inflammatory interleukin 10 (IL-10)-secreting neutrophils but also promoted the interaction of invariant natural killer T cells (iNKT cells) with those neutrophils, a process that limited their suppressive activity by diminishing the production of IL-10 and enhancing the production of IL-12. Because SAA-1-producing melanomas promoted differentiation of IL-10-secreting neutrophils, harnessing iNKT cells could be useful therapeutically by decreasing the frequency of immunosuppressive neutrophils and restoring tumor-specific immune responses.